Researchers at the National Renewable Energy Laboratory (NREL) have received a nearly $3 million award from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) to study a biorefining process that plans to increase fuel yields and recycle carbon dioxide (CO2).

As demand increases for a low-carbon biofuel, NREL have partnered with the University of Oregon, Genomatica and DeNore to lead a project that aims to utilise electrochemistry in the sugar fermentation process to produce lipids used to create biofuels.

During the fermentation processes that use biomass to make renewable diesel and sustainable aviation fuel (SAF) as much as one-third of the carbon in sugar is lost as CO2. This project aims to eliminate this loss, which will not only reduce the amount of CO2 emitted into the atmosphere but will also allow retention of as much carbon as possible in the fuel itself, thereby increasing yields.

Formate driving the conversion process.

Formate driving the conversion process.

The key to the project realising such technology lies in the world of electrochemistry. An electrochemical cell, powered by renewable electricity, can convert recycled CO2 into formate. Formate is an ester that promotes the fermentation of sugar in a bioreactor. As formate breaks down during the fermentation process, CO2 is released as by-product and is then fed back to the electrochemical cell to create new formate.

Commenting on the research, Randy Cortright, Senior Research Advisor, NREL, said, “With today’s technologies, a lot of carbon is wasted as CO2 during biomass fermentation.”

“We want to put that waste carbon to good use by integrating sugar fermentation with electrochemistry to synthesise lipids used to make biofuel. Formate anchors the process, as it lets use recycle CO2 nearly indefinitely.”

Using the combined expertise of all partners involved, the researchers hope to see the project resulting in formate being seen as an asset when enhancing yields and recycling CO2.

Cortright also said, “This could be a critical milestone not only because it can help meet increased demand for SAF and other renewable biofuels. It can actually lower those fuels’ carbon footprints.”

Funding for the project is being supplied by ARPA-E’s Energy and Carbon Optimized Synthesis for the Bioeconomy programme, which aims to engineer more efficient biomass conversion platforms, in addition to reducing emissions from the process.

As demand grows for renewable diesel and SAF, this technology could be an important landmark in the use of electrochemistry to decarbonise industrial refining processes.